Ready to dry camp. Need 6V AGM battery recommendations

Hi there!
I've replaced the stock converter with a multi-charge one.  I've order a dual 6v battery box and it's been shipped and is on the way.

Now I just need a couple of nice 6V AGMs. I'm interested the least amount of battery maintenance as possible. I plan to dry camp 4-5 days at a time.

I did a few internet searches and found this: VMAXTANKS 6 Volt 225Ah AGM

Does anyone have any experience with these or have another recommendation?

Thanks!

Why AGM??  A golf cart battery from Costco or Sam's Club works just fine. 

The important part of battery maintenance is "Keeping the batteries fully charged!"  Checking the water level once a month or so in a non-AGM battery in a very minor issue.

No matter an AGM or a flooded cell you are going to have to WORK to keep the battery charged during a 4-5 day stay.

Not keeping the battery fully charged every day will ruin an AGM just about as quickly as a inexpensive flooded cell.

AStravelers said:

Why AGM??  A golf cart battery from Costco or Sam's Club works just fine.

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I agree with AStavelers.
AGM is a Sealed Valve Regulated Lead Acid.  Heaven forbid you boild 'em dry but if you do they are done. and as they are "Starved electrolytic" it don't take much boiling.  They are very expensive compared to flooded wet.  You are really paying a lot of money to get out of a little maintenance. 

unless you have a real pressing need to use AGM then I would suggest standard GC2 FLA ( aka. golf cart batteries )
AGM cost approx twice that of FLA and have a shorter lifespan.

the maintenance on FLA is very minimal, I check mine every three months and have yet to add water this year..

4 to 5 days is ok as long as you can avoid discharging below 50% DOD. else you will sacrifice lifespan.

those details may not be an issue for you, it's your money, spend it how you please.. but take note of
experienced advice before you commit.

BTW. a pressing need might be:--

1. you need higher charge and discharge currents than a FLA can provide.
2. you cannot tolerate any acid spillage WHATSOEVER due to location ( such as an aircraft )
3. you are dead ass lazy, have plenty of money to burn and have no interest in batteries.

He stated he wants the least amount of maintenance possible, ergo AGM is the way to go.  Just be aware that an AGM typically has less amp-hour capacity than a flooded cell of the same size, even though it costs considerably more.

That said, I agree that maintenance for a flooded cell GC2 (golf car) battery should be minimal with a good quality charger. However, he still has to check it, even if it seldom needs additional distilled water. Plus, a flooded cell always produces a certain amount of electrolyte mist on nearby surfaces, whereas an AGM is externally dry.

I had saw somewhere that AGMs charge faster.  If I was boondocking, I thought this would be a benefit in terms of running a generator less to get them charged again. Is this not the case? 

On my camper, I'll need to remove the propane tanks in order to be able to install the 6 volts. Would I need to bring the AGMs inside the garage for the winter?  I know I would for the regular FLA.

There is a Battery Plus near me. They have the Trojan T105s and a Duracell 6v. 

Thanks for your help with this.

AGMs will generally accept a higher rate of bulk charge than a flooded cell, but that has little effect on the total time to do a 100% recharge.  However, boondockers charging via generator often don't get back above about 80% anyway, so the AGM might cut some minutes off reaching that level.  It's not going to be a big factor, though.

So then what are the advantages of AGMs?

All50States said:

So then what are the advantages of AGMs?

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1. NO spillage
2. you can install them in any orientation
3. charge and discharge is 50% higher than FLA typically.
4. almost no venting unless you overcharge and push the charging voltage into the gassing region
5. no equalizing required ( although there are a few that are capable )
6. NO water maintenance ever..

cons:

1. can be 200% the cost of FLA
2. lower lifespan compared to FLA
3. easy to abuse, overcharging will vent electrolyte
4. somewhat difficult to accurately measure state of charge

solarman, can you discharge AGMS greater than 50%?  If not, other then minor maintenance, it sounds like the T105s would be fine.  Any other GC2 FLA I should look at?  Is there much difference in quality between MFRs?

AGMs can be discharged to 50%, but like other deep cycle flooded batteries, they should be fully recharged soon therafter. Deep cycle batteries can survive repeated deep discharges better than "standard" lead/acid batteies, but it will shorten their lives. It's better to not discharge them so deeply. 

I've never used 6 volt golf cart batteries, but I've used a variety of 12 volt batteries. Our coach has eight Group 31, 12 volt AGM house batteries (105 AH each) and our last set lasted a little more than seven years. As others have said, checking and refilling flooded cell batteries is not a difficult task, but it's one that must be done on a regular basis if you want your batteries to live a long life. Not so with AGMs. The only thing I do is blow the dust off them once a year, and check their cables. They're truly maintenance free.

They're about twice the price of standard lead/acid batteies, but a lot cheaper than Li batteries. We can accurately determine our battery's SOC, at a glance, with our Trimetric RV2030 battery monitor. Our Magnum 2812 has two AGM charging profiles (we use Type 2) and we've never had any overcharging problems at all  - even in 100+ or sub 0 temps.

At home, the coach is always plugged in, so the batteries are always fully charged. When camping, 95% (or more) of our charging is done via solar with an Outback controller that's programmed with an AGM charging profile. No charging problems at all. Some say they charge their AGMs with a standard lead/acid battery charger, using standard (non AGM) charging profiles. They claim to have had no overcharging problems, but I can't help but wonder if it has shortened their AGM's lives a bit.

I'll likely switch to Li batteries someday, when some of the temp and cost issues are resolved, but I'll never go back to standard lead/acid batteies. I really like our AGMs. FWIW

Kev

All50States said:

solarman, can you discharge AGMS greater than 50%?  If not, other then minor maintenance, it sounds like the T105s would be fine.  Any other GC2 FLA I should look at?  Is there much difference in quality between MFRs?

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typically charge rates should not exceed 4/C and discharge can be up to 1/C

so for a 100 a/hr battery this equates to 25 amps charge and 100 amps discharge

the usual Peukert factor applies of course as it's still a lead acid battery.

of course, abuse like this will shorten lifespan.. so is not recommended on a daily basis..


other FLA to consider:

1. Crown
2. Rolls surrette
3. Deka
3. US Battery
4. Universal Battery ( UB )
5. Duracell

AGM:

1. Concorde lifeline
2. Trojan
3. Rolls surrette
4. US battery
5. UB


for a good all round battery then Crown is a good choice.

top of the line FLA: Trojan or Rolls
top of the line AGM: Concorde Lifeline.

can you discharge AGMS greater than 50%?

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Time for my 50% sermon again. 
You can discharge any lead-acid battery to 50% or beyond - there is nothing magic about that number.It's just a convenient reminder that the deeper you discharge, the shorter the battery lifetime.  50% still hurts more than 40%, and 60% hurts more than 50%. Whether flooded or AGM or Gel.    AGMs retain their electrolyte better and keep it where it needs to be (between the plates), so they hold up somewhat better in hard use. They rarely suffer from sulfating either.  I'll let others debate how deep you can go, as long as you remember that deeper is always worse and there will be an ultimate price to pay.

For my dry camping needs, would it be safe to say that something like the T105s would do well for me.  I would be dry camping about 3 times a year.  Just wanted something that would give me enough power.  I plan on getting a generator.

If I have to store the FLAs in the garage during the winter, then I would need to take off my propane tanks in order to get to the batteries.  That was one of the reasons I originally thought AGMs would do the trick and I could leave them in my camper during the winter. 

A pair of Trojan T105 (or equivalent GC2 deep cycle) provides 225 AH of power.  Whether that's "enough" depends on your usage, but it would probably last many campers 2-3 days. Maybe more if no furnace use and limited lighting. Since you will have a generator, you can recharge as needed. I'd plan on daily, keeping the batteries near full.

Whether FLA or AGM, the batteries need to have their charge maintained while in storage, winter or otherwise. They can stay on the RV, but they need at least a maintenance charger connected.

If this is your first time extensively using batteries, I suggest you start with an inexpensive set of golf cart batteries.  Sam's Club, Costco and Batteries Plus have Duracell GC2 golf cart batteries for $80-100.

With proper care and usage, they'll perform well and last almost as long as the Trojans.  However, if you should goof somewhere along the line and damage them or do something that shortens their life, your wallet will take a smaller hit.

If you go with FLA batteries, I recommend you get and use Water-Miser caps as they significantly will reduce the water use and corrosion from the battery acid.  I had them in my Dutch star and cleaning the battery box area was a once a year job and little or no corrosion.

Good advice from Lou - there is very little difference between premium grade golf car batteries and run-of-the-mill private brands. The only caveat to that is to notice the amp-hour ratings. One way to make a battery cheaper is to reduce the amount of lead plates inside, and that always reduces the AH rating.  Common AH ratings are 210 and 225, but there are also some that are 240-260 (the latter are physically taller as well as having more lead).

Here's another piece of advice... before you spend any money on a different type of battery, measure your battery compartment. I don't know what kind of RV you have, but 6 volt golf cart batteries are physically taller than what you probably have now. They won't fit in some RV battery compartments - like ours.

Kev

Based on your guidance, I'll got with FLA batteries.

Batteries Plus has 230AH Duracell batteries for $120.  I'll order online and get a 10% discount.  Glad that decision has been made. 

Thanks again.